/*

 * Copyright © 2004 Keith Packard

 * Copyright © 2008 Red Hat, Inc.

 *

 * This library is free software; you can redistribute it and/or

 * modify it either under the terms of the GNU Lesser General Public

 * License version 2.1 as published by the Free Software Foundation

 * (the "LGPL") or, at your option, under the terms of the Mozilla

 * Public License Version 1.1 (the "MPL"). If you do not alter this

 * notice, a recipient may use your version of this file under either

 * the MPL or the LGPL.

 *

 * You should have received a copy of the LGPL along with this library

 * in the file COPYING-LGPL-2.1; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA

 * You should have received a copy of the MPL along with this library

 * in the file COPYING-MPL-1.1

 *

 * The contents of this file are subject to the Mozilla Public License

 * Version 1.1 (the "License"); you may not use this file except in

 * compliance with the License. You may obtain a copy of the License at

 * http://www.mozilla.org/MPL/

 *

 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY

 * OF ANY KIND, either express or implied. See the LGPL or the MPL for

 * the specific language governing rights and limitations.

 *

 * The Original Code is the cairo graphics library.

 *

 * The Initial Developer of the Original Code is Keith Packard

 *

 * Contributor(s):

 *      Keith Packard <keithp@keithp.com>

 *      Behdad Esfahbod <behdad@behdad.org>

 */

#include "cairoint.h"

#include "cairo-error-private.h"

#include <math.h>

/*

 * This file implements a user-font rendering the descendant of the Hershey

 * font coded by Keith Packard for use in the Twin window system.

 * The actual font data is in cairo-font-face-twin-data.c

 *

 * Ported to cairo user font and extended by Behdad Esfahbod.

 */

static cairo_user_data_key_t twin_properties_key;

/*

 * Face properties

 */

/* We synthesize multiple faces from the twin data.  Here is the parameters. */

/* The following tables and matching code are copied from Pango */

/* CSS weight */

typedef enum {

  TWIN_WEIGHT_THIN = 100,

  TWIN_WEIGHT_ULTRALIGHT = 200,

  TWIN_WEIGHT_LIGHT = 300,

  TWIN_WEIGHT_BOOK = 380,

  TWIN_WEIGHT_NORMAL = 400,

  TWIN_WEIGHT_MEDIUM = 500,

  TWIN_WEIGHT_SEMIBOLD = 600,

  TWIN_WEIGHT_BOLD = 700,

  TWIN_WEIGHT_ULTRABOLD = 800,

  TWIN_WEIGHT_HEAVY = 900,

  TWIN_WEIGHT_ULTRAHEAVY = 1000

} twin_face_weight_t;

/* CSS stretch */

typedef enum {

  TWIN_STRETCH_ULTRA_CONDENSED,

  TWIN_STRETCH_EXTRA_CONDENSED,

  TWIN_STRETCH_CONDENSED,

  TWIN_STRETCH_SEMI_CONDENSED,

  TWIN_STRETCH_NORMAL,

  TWIN_STRETCH_SEMI_EXPANDED,

  TWIN_STRETCH_EXPANDED,

  TWIN_STRETCH_EXTRA_EXPANDED,

  TWIN_STRETCH_ULTRA_EXPANDED

} twin_face_stretch_t;

typedef struct

{

  int value;

  const char str[16];

} FieldMap;

static const FieldMap slant_map[] = {

  { CAIRO_FONT_SLANT_NORMAL, "" },

  { CAIRO_FONT_SLANT_NORMAL, "Roman" },

  { CAIRO_FONT_SLANT_OBLIQUE, "Oblique" },

  { CAIRO_FONT_SLANT_ITALIC, "Italic" }

};

static const FieldMap smallcaps_map[] = {

  { FALSE, "" },

  { TRUE, "Small-Caps" }

};

static const FieldMap weight_map[] = {

  { TWIN_WEIGHT_THIN, "Thin" },

  { TWIN_WEIGHT_ULTRALIGHT, "Ultra-Light" },

  { TWIN_WEIGHT_ULTRALIGHT, "Extra-Light" },

  { TWIN_WEIGHT_LIGHT, "Light" },

  { TWIN_WEIGHT_BOOK, "Book" },

  { TWIN_WEIGHT_NORMAL, "" },

  { TWIN_WEIGHT_NORMAL, "Regular" },

  { TWIN_WEIGHT_MEDIUM, "Medium" },

  { TWIN_WEIGHT_SEMIBOLD, "Semi-Bold" },

  { TWIN_WEIGHT_SEMIBOLD, "Demi-Bold" },

  { TWIN_WEIGHT_BOLD, "Bold" },

  { TWIN_WEIGHT_ULTRABOLD, "Ultra-Bold" },

  { TWIN_WEIGHT_ULTRABOLD, "Extra-Bold" },

  { TWIN_WEIGHT_HEAVY, "Heavy" },

  { TWIN_WEIGHT_HEAVY, "Black" },

  { TWIN_WEIGHT_ULTRAHEAVY, "Ultra-Heavy" },

  { TWIN_WEIGHT_ULTRAHEAVY, "Extra-Heavy" },

  { TWIN_WEIGHT_ULTRAHEAVY, "Ultra-Black" },

  { TWIN_WEIGHT_ULTRAHEAVY, "Extra-Black" }

};

static const FieldMap stretch_map[] = {

  { TWIN_STRETCH_ULTRA_CONDENSED, "Ultra-Condensed" },

  { TWIN_STRETCH_EXTRA_CONDENSED, "Extra-Condensed" },

  { TWIN_STRETCH_CONDENSED,       "Condensed" },

  { TWIN_STRETCH_SEMI_CONDENSED,  "Semi-Condensed" },

  { TWIN_STRETCH_NORMAL,          "" },

  { TWIN_STRETCH_SEMI_EXPANDED,   "Semi-Expanded" },

  { TWIN_STRETCH_EXPANDED,        "Expanded" },

  { TWIN_STRETCH_EXTRA_EXPANDED,  "Extra-Expanded" },

  { TWIN_STRETCH_ULTRA_EXPANDED,  "Ultra-Expanded" }

};

static const FieldMap monospace_map[] = {

  { FALSE, "" },

  { TRUE, "Mono" },

  { TRUE, "Monospace" }

};

typedef struct _twin_face_properties {

    cairo_font_slant_t  slant;

    twin_face_weight_t  weight;

    twin_face_stretch_t stretch;

    /* lets have some fun */

    cairo_bool_t monospace;

    cairo_bool_t smallcaps;

} twin_face_properties_t;

static cairo_bool_t

field_matches (const char *s1,

               const char *s2,

               int len)

{

  int c1, c2;

  while (len && *s1 && *s2)

    {

#define TOLOWER(c) \

   (((c) >= 'A' && (c) <= 'Z') ? (c) - 'A' + 'a' : (c))

      c1 = TOLOWER (*s1);

      c2 = TOLOWER (*s2);

      if (c1 != c2) {

        if (c1 == '-') {

          s1++;

          continue;

        }

        return FALSE;

      }

      s1++; s2++;

      len--;

    }

  return len == 0 && *s1 == '\0';

}

static cairo_bool_t

parse_int (const char *word,

     size_t      wordlen,

     int        *out)

{

  char *end;

  long val = strtol (word, &end, 10);

  int i = val;

  if (end != word && (end == word + wordlen) && val >= 0 && val == i)

    {

      if (out)

        *out = i;

      return TRUE;

    }

  return FALSE;

}

static cairo_bool_t

find_field (const char *what,

      const FieldMap *map,

      int n_elements,

      const char *str,

      int len,

      int *val)

{

  int i;

  cairo_bool_t had_prefix = FALSE;

  if (what)

    {

      i = strlen (what);

      if (len > i && 0 == strncmp (what, str, i) && str[i] == '=')

  {

    str += i + 1;

    len -= i + 1;

    had_prefix = TRUE;

  }

    }

  for (i=0; i<n_elements; i++)

    {

      if (map[i].str[0] && field_matches (map[i].str, str, len))

  {

    if (val)

      *val = map[i].value;

    return TRUE;

  }

    }

  if (!what || had_prefix)

    return parse_int (str, len, val);

  return FALSE;

}

static void

parse_field (twin_face_properties_t *props,

       const char *str,

       int len)

{

  if (field_matches ("Normal", str, len))

    return;

#define FIELD(NAME) \

  if (find_field (STRINGIFY (NAME), NAME##_map, ARRAY_LENGTH (NAME##_map), str, len, \

      (int *)(void *)&props->NAME)) \

      return; \

  FIELD (weight);

  FIELD (slant);

  FIELD (stretch);

  FIELD (smallcaps);

  FIELD (monospace);

#undef FIELD

}

static void

face_props_parse (twin_face_properties_t *props,

       const char *s)

{

    const char *start, *end;

    for (start = end = s; *end; end++) {

  if (*end != ' ' && *end != ':')

      continue;

  if (start < end)

    parse_field (props, start, end - start);

  start = end + 1;

    }

    if (start < end)

      parse_field (props, start, end - start);

}

static twin_face_properties_t *

twin_font_face_create_properties (cairo_font_face_t *twin_face)

{

    twin_face_properties_t *props;

    props = _cairo_malloc (sizeof (twin_face_properties_t));

    if (unlikely (props == NULL))

  return NULL;

    props->stretch  = TWIN_STRETCH_NORMAL;

    props->slant = CAIRO_FONT_SLANT_NORMAL;

    props->weight = TWIN_WEIGHT_NORMAL;

    props->monospace = FALSE;

    props->smallcaps = FALSE;

    if (unlikely (cairo_font_face_set_user_data (twin_face,

              &twin_properties_key,

              props, free))) {

  free (props);

  return NULL;

    }

    return props;

}

static cairo_status_t

twin_font_face_set_properties_from_toy (cairo_font_face_t *twin_face,

          cairo_toy_font_face_t *toy_face)

{

    twin_face_properties_t *props;

    props = twin_font_face_create_properties (twin_face);

    if (unlikely (props == NULL))

  return _cairo_error (CAIRO_STATUS_NO_MEMORY);

    props->slant = toy_face->slant;

    props->weight = toy_face->weight == CAIRO_FONT_WEIGHT_NORMAL ?

        TWIN_WEIGHT_NORMAL : TWIN_WEIGHT_BOLD;

    face_props_parse (props, toy_face->family);

    return CAIRO_STATUS_SUCCESS;

}

/*

 * Scaled properties

 */

typedef struct _twin_scaled_properties {

  twin_face_properties_t *face_props;

  cairo_bool_t snap; /* hint outlines */

  double weight; /* unhinted pen width */

  double penx, peny; /* hinted pen width */

  double marginl, marginr; /* hinted side margins */

  double stretch; /* stretch factor */

} twin_scaled_properties_t;

static void

compute_hinting_scale (cairo_t *cr,

           double x, double y,

           double *scale, double *inv)

{

    cairo_user_to_device_distance (cr, &x, &y);

    *scale = x == 0 ? y : y == 0 ? x :sqrt (x*x + y*y);

    *inv = 1 / *scale;

}

static void

compute_hinting_scales (cairo_t *cr,

      double *x_scale, double *x_scale_inv,

      double *y_scale, double *y_scale_inv)

{

    double x, y;

    x = 1; y = 0;

    compute_hinting_scale (cr, x, y, x_scale, x_scale_inv);

    x = 0; y = 1;

    compute_hinting_scale (cr, x, y, y_scale, y_scale_inv);

}

#define SNAPXI(p) (_cairo_round ((p) * x_scale) * x_scale_inv)

#define SNAPYI(p) (_cairo_round ((p) * y_scale) * y_scale_inv)

/* This controls the global font size */

#define F(g)    ((g) / 72.)

static void

twin_hint_pen_and_margins(cairo_t *cr,

        double *penx, double *peny,

        double *marginl, double *marginr)

{

    double x_scale, x_scale_inv;

    double y_scale, y_scale_inv;

    double margin;

    compute_hinting_scales (cr,

          &x_scale, &x_scale_inv,

          &y_scale, &y_scale_inv);

    *penx = SNAPXI (*penx);

    if (*penx < x_scale_inv)

  *penx = x_scale_inv;

    *peny = SNAPYI (*peny);

    if (*peny < y_scale_inv)

  *peny = y_scale_inv;

    margin = *marginl + *marginr;

    *marginl = SNAPXI (*marginl);

    if (*marginl < x_scale_inv)

  *marginl = x_scale_inv;

    *marginr = margin - *marginl;

    if (*marginr < 0)

  *marginr = 0;

    *marginr = SNAPXI (*marginr);

}

static cairo_status_t

twin_scaled_font_compute_properties (cairo_scaled_font_t *scaled_font,

             cairo_t           *cr)

{

    cairo_status_t status;

    twin_scaled_properties_t *props;

    props = _cairo_malloc (sizeof (twin_scaled_properties_t));

    if (unlikely (props == NULL))

  return _cairo_error (CAIRO_STATUS_NO_MEMORY);

    props->face_props = cairo_font_face_get_user_data (cairo_scaled_font_get_font_face (scaled_font),

                   &twin_properties_key);

    props->snap = scaled_font->options.hint_style > CAIRO_HINT_STYLE_NONE;

    /* weight */

    props->weight = props->face_props->weight * (F (4) / TWIN_WEIGHT_NORMAL);

    /* pen & margins */

    props->penx = props->peny = props->weight;

    props->marginl = props->marginr = F (4);

    if (scaled_font->options.hint_style > CAIRO_HINT_STYLE_SLIGHT)

  twin_hint_pen_and_margins(cr,

          &props->penx, &props->peny,

          &props->marginl, &props->marginr);

    /* stretch */

    props->stretch = 1 + .1 * ((int) props->face_props->stretch - (int) TWIN_STRETCH_NORMAL);

    /* Save it */

    status = cairo_scaled_font_set_user_data (scaled_font,

                &twin_properties_key,

                props, free);

    if (unlikely (status))

  goto FREE_PROPS;

    return CAIRO_STATUS_SUCCESS;

FREE_PROPS:

    free (props);

    return status;

}

/*

 * User-font implementation

 */

static cairo_status_t

twin_scaled_font_init (cairo_scaled_font_t  *scaled_font,

           cairo_t              *cr,

           cairo_font_extents_t *metrics)

{

  metrics->ascent  = F (54);

  metrics->descent = 1 - metrics->ascent;

  return twin_scaled_font_compute_properties (scaled_font, cr);

}

#define TWIN_GLYPH_MAX_SNAP_X 4

#define TWIN_GLYPH_MAX_SNAP_Y 7

typedef struct {

    int n_snap_x;

    int8_t snap_x[TWIN_GLYPH_MAX_SNAP_X];

    double snapped_x[TWIN_GLYPH_MAX_SNAP_X];

    int n_snap_y;

    int8_t snap_y[TWIN_GLYPH_MAX_SNAP_Y];

    double snapped_y[TWIN_GLYPH_MAX_SNAP_Y];

} twin_snap_info_t;

#define twin_glyph_left(g)      ((g)[0])

#define twin_glyph_right(g)     ((g)[1])

#define twin_glyph_ascent(g)    ((g)[2])

#define twin_glyph_descent(g)   ((g)[3])

#define twin_glyph_n_snap_x(g)  ((g)[4])

#define twin_glyph_n_snap_y(g)  ((g)[5])

#define twin_glyph_snap_x(g)    (&g[6])

#define twin_glyph_snap_y(g)    (twin_glyph_snap_x(g) + twin_glyph_n_snap_x(g))

#define twin_glyph_draw(g)      (twin_glyph_snap_y(g) + twin_glyph_n_snap_y(g))

static void

twin_compute_snap (cairo_t             *cr,

       twin_snap_info_t    *info,

       const signed char   *b)

{

    int     s, n;

    const signed char *snap;

    double x_scale, x_scale_inv;

    double y_scale, y_scale_inv;

    compute_hinting_scales (cr,

          &x_scale, &x_scale_inv,

          &y_scale, &y_scale_inv);

    snap = twin_glyph_snap_x (b);

    n = twin_glyph_n_snap_x (b);

    info->n_snap_x = n;

    assert (n <= TWIN_GLYPH_MAX_SNAP_X);

    for (s = 0; s < n; s++) {

  info->snap_x[s] = snap[s];

  info->snapped_x[s] = SNAPXI (F (snap[s]));

    }

    snap = twin_glyph_snap_y (b);

    n = twin_glyph_n_snap_y (b);

    info->n_snap_y = n;

    assert (n <= TWIN_GLYPH_MAX_SNAP_Y);

    for (s = 0; s < n; s++) {

  info->snap_y[s] = snap[s];

  info->snapped_y[s] = SNAPYI (F (snap[s]));

    }

}

static double

twin_snap (int8_t v, int n, int8_t *snap, double *snapped)

{

    int s;

    if (!n)

  return F(v);

    if (snap[0] == v)

  return snapped[0];

    for (s = 0; s < n - 1; s++)

    {

  if (snap[s+1] == v)

      return snapped[s+1];

  if (snap[s] <= v && v <= snap[s+1])

  {

      int before = snap[s];

      int after = snap[s+1];

      int dist = after - before;

      double snap_before = snapped[s];

      double snap_after = snapped[s+1];

      double dist_before = v - before;

      return snap_before + (snap_after - snap_before) * dist_before / dist;

  }

    }

    return F(v);

}

#define SNAPX(p)  twin_snap (p, info.n_snap_x, info.snap_x, info.snapped_x)

#define SNAPY(p)  twin_snap (p, info.n_snap_y, info.snap_y, info.snapped_y)

static cairo_status_t

twin_scaled_font_render_glyph (cairo_scaled_font_t  *scaled_font,

             unsigned long         glyph,

             cairo_t              *cr,

             cairo_text_extents_t *metrics)

{

    double x1, y1, x2, y2, x3, y3;

    double marginl;

    twin_scaled_properties_t *props;

    twin_snap_info_t info;

    const int8_t *b;

    const int8_t *g;

    int8_t w;

    double gw;

    props = cairo_scaled_font_get_user_data (scaled_font, &twin_properties_key);

    /* Save glyph space, we need it when stroking */

    cairo_save (cr);

    /* center the pen */

    cairo_translate (cr, props->penx * .5, -props->peny * .5);

    /* small-caps */

    if (props->face_props->smallcaps && glyph >= 'a' && glyph <= 'z') {

  glyph += 'A' - 'a';

  /* 28 and 42 are small and capital letter heights of the glyph data */

  cairo_scale (cr, 1, 28. / 42);

    }

    /* slant */

    if (props->face_props->slant != CAIRO_FONT_SLANT_NORMAL) {

  cairo_matrix_t shear = { 1, 0, -.2, 1, 0, 0};

  cairo_transform (cr, &shear);

    }

    b = _cairo_twin_outlines +

  _cairo_twin_charmap[unlikely (glyph >= ARRAY_LENGTH (_cairo_twin_charmap)) ? 0 : glyph];

    g = twin_glyph_draw(b);

    w = twin_glyph_right(b);

    gw = F(w);

    marginl = props->marginl;

    /* monospace */

    if (props->face_props->monospace) {

  double monow = F(24);

  double extra =  props->penx + props->marginl + props->marginr;

  cairo_scale (cr, (monow + extra) / (gw + extra), 1);

  gw = monow;

  /* resnap margin for new transform */

  {

      double x, y, x_scale, x_scale_inv;

      x = 1; y = 0;

      compute_hinting_scale (cr, x, y, &x_scale, &x_scale_inv);

      marginl = SNAPXI (marginl);

  }

    }

    cairo_translate (cr, marginl, 0);

    /* stretch */

    cairo_scale (cr, props->stretch, 1);

    if (props->snap)

  twin_compute_snap (cr, &info, b);

    else

  info.n_snap_x = info.n_snap_y = 0;

    /* advance width */

    metrics->x_advance = gw * props->stretch + props->penx + props->marginl + props->marginr;

    /* glyph shape */

    for (;;) {

  switch (*g++) {

  case 'M':

      cairo_close_path (cr);

      /* fall through */

  case 'm':

      x1 = SNAPX(*g++);

      y1 = SNAPY(*g++);

      cairo_move_to (cr, x1, y1);

      continue;

  case 'L':

      cairo_close_path (cr);

      /* fall through */

  case 'l':

      x1 = SNAPX(*g++);

      y1 = SNAPY(*g++);

      cairo_line_to (cr, x1, y1);

      continue;

  case 'C':

      cairo_close_path (cr);

      /* fall through */

  case 'c':

      x1 = SNAPX(*g++);

      y1 = SNAPY(*g++);

      x2 = SNAPX(*g++);

      y2 = SNAPY(*g++);

      x3 = SNAPX(*g++);

      y3 = SNAPY(*g++);

      cairo_curve_to (cr, x1, y1, x2, y2, x3, y3);

      continue;

  case 'E':

      cairo_close_path (cr);

      /* fall through */

  case 'e':

      cairo_restore (cr); /* restore glyph space */

      cairo_set_tolerance (cr, 0.01);

      cairo_set_line_join (cr, CAIRO_LINE_JOIN_ROUND);

      cairo_set_line_cap (cr, CAIRO_LINE_CAP_ROUND);

      cairo_set_line_width (cr, 1);

      cairo_scale (cr, props->penx, props->peny);

      cairo_stroke (cr);

      break;

  case 'X':

      /* filler */

      continue;

  }

  break;

    }

    return CAIRO_STATUS_SUCCESS;

}

static cairo_status_t

twin_scaled_font_unicode_to_glyph (cairo_scaled_font_t *scaled_font,

           unsigned long        unicode,

           unsigned long       *glyph)

{

    /* We use an identity charmap.  Which means we could live

     * with no unicode_to_glyph method too.  But we define this

     * to map all unknown chars to a single unknown glyph to

     * reduce pressure on cache. */

    if (likely (unicode < ARRAY_LENGTH (_cairo_twin_charmap)))

  *glyph = unicode;

    else

  *glyph = 0;

    return CAIRO_STATUS_SUCCESS;

}

/*

 * Face constructor

 */

static cairo_font_face_t *

_cairo_font_face_twin_create_internal (void)

{

    cairo_font_face_t *twin_font_face;

    twin_font_face = cairo_user_font_face_create ();

    cairo_user_font_face_set_init_func             (twin_font_face, twin_scaled_font_init);

    cairo_user_font_face_set_render_glyph_func     (twin_font_face, twin_scaled_font_render_glyph);

    cairo_user_font_face_set_unicode_to_glyph_func (twin_font_face, twin_scaled_font_unicode_to_glyph);

    return twin_font_face;

}

cairo_font_face_t *

_cairo_font_face_twin_create_fallback (void)

{

    cairo_font_face_t *twin_font_face;

    twin_font_face = _cairo_font_face_twin_create_internal ();

    if (! twin_font_face_create_properties (twin_font_face)) {

  cairo_font_face_destroy (twin_font_face);

  return (cairo_font_face_t *) &_cairo_font_face_nil;

    }

    return twin_font_face;

}

cairo_status_t

_cairo_font_face_twin_create_for_toy (cairo_toy_font_face_t   *toy_face,

              cairo_font_face_t      **font_face)

{

    cairo_status_t status;

    cairo_font_face_t *twin_font_face;

    twin_font_face = _cairo_font_face_twin_create_internal ();

    status = twin_font_face_set_properties_from_toy (twin_font_face, toy_face);

    if (status) {

  cairo_font_face_destroy (twin_font_face);

  return status;

    }

    *font_face = twin_font_face;

    return CAIRO_STATUS_SUCCESS;

}